Blood Pressure Regulation System Lacking in Black Youth

Kathleen Blanchard's picture

Researchers are not yet sure why, but a new study shows that one third of otherwise healthy black adolescents lack salt regulation by the kidneys, necessary to keep blood pressure in check. The kidneys help the body eliminate more salt, but in some black youth, the natural mechanism for salt regulation by the kidneys is absent, placing them at risk for hypertension in adulthood.

Dr. Matthew Diamond, nephrology fellow in the Medical College of Georgia School of Medicine will presented the findings May 8 at the American Society of Hypertension 24th Annual Scientific Program in San Francisco. Dr. Diamond explains, "The way it's supposed to work is the higher your blood pressure goes, the system is supposed to be suppressed so you urinate out more sodium and the blood pressure goes down in response." However, they found kidney salt regulation lacking in a significant number of black youth.


When researchers from the Medical College of Georgia measured hormones in 168 15-18-year-olds with normal pressures and on sodium- and potassium- controlled diets for two weeks, they found that approximately one third of black adolescents lacked regulation of salt by the kidneys from the renin-angiotensin-aldosterone system. The researcher measured hormonal response after adolescents played video games to induce environmental stress, measuring hormones in urine and blood, and taking blood pressure readings two hours later.

The researchers ruled out adrenaline as the cause by also observing heart rate. They found that it was not the “fight or flight” response keeping blood pressures higher. The study included adolescents who were not obese, also ruling out the possibility of aldosterone produced by fat as a factor causing lack of salt excretion among a high number of black adolescents.

Dr. Diamonds says, "There is nothing we know about that is explaining what we are seeing yet we have some pathology here that could potentially explain difficult hypertension in kids.” The researchers plan to screen study participants to see if they can figure out where the problem lies, and how to target those at high risk for hypertension as adults. ." He says the reason that adolescents, and especially black youth seem to lack proper regulation of salt by the kidneys may be the result of a genetic mutation.

Medical College Of Georgia